For what purpose are bonds primarily utilized in investment portfolios?

Bonds are primarily utilized in investment portfolios to diversify and provide income through cash flows. This is because bonds generally offer a more stable income stream compared to stocks, as they pay regular interest (coupon payments) to investors. This steady cash flow can help balance the overall risk of an investment portfolio, particularly during times when stock markets are volatile.

The diversification aspect of bonds stems from their lower correlation with equities. When stocks might be experiencing a downturn, bonds can hold their value or even appreciate, thereby reducing the overall risk of the portfolio. This balance can be particularly important for risk-averse investors or those seeking to preserve capital while generating income.

Additionally, bonds can be an attractive investment option for individuals nearing retirement or those who require predictable cash flows to meet regular expenses. The regular interest payments can provide a reliable source of income that is less tied to the market's fluctuations compared to stocks.

Considering the other options, while bonds can play roles in increasing leverage or speculation on interest rate changes, these are not their primary purposes within a typical investment strategy. The primary focus remains on diversification and income generation, making option C the most accurate representation of the role of bonds in investment portfolios.